PHILADELPHIA - Surveillance video captured the moment a man was knocked unconscious, then robbed by two suspects on the streets of North Philadelphia earlier this month.The 62-year-old victim was walking on 12th Street and Girard when he was approached from behind and punched in the face by one of the suspects.He was "hit with such force" that he hit his head on a nearby wall and was knocked unconscious, according to authorities.MORE HEADLINES:Police say the suspects stole his wallet and phone, then fled, leaving the critically injured man on the sidewalk.The victim was treated for multiple face fractures and brain bleeding at a local hospital.Police are still looking for both suspects, and ask anyone with information to contact them..